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Cockerel. Not technically a rooster (or hen) until a year old.. terms matter especially when discussing behavior and health.. otherwise we generally just say hen and roo also.
Sorry for your loss, It wasn't him that did it. Many predators can get through chicken wire including rats.. start another thread to find the culprit.
You might also want to discuss your current interaction with him and see if there's something that should be switched up to keep him from acting stupid towards you. I don't buy all the dominance stuff but getting communication right and understanding what's being communicated can help a lot. I've had a few Stew Pidasso's.. that would come all the way across the pasture to attack my dog playing frisbee and crow every time they saw me and indeed became stew.. but generally speaking I've also had a lot of really good boys that were valued and protective members of the flock and with enough discernment to stand guard and gripe some but not attack family, visitors, or other pets. Roosters are not adequate predator protection in my location.